In the previous paper, a method for estimating fatigue strength under random loading condition was proposed, a method that combined fatigue tests with calculations. The loading condition is limited to the case where the mean stress level, or the stress ratio of the minimum stress to the maximum stress, is constant. However, in the actual service loading condition, both mean stress and stress amplitude generally vary from cycle to cycle. Therefore, a random fatigue test with a constant mean stress or stress ratio is not enough to clarify fatigue behavior under actual service loading conditions. In this paper, a random test procedure similar to the method shown in the previous paper is proposed. However, the new-procedure both mean stress and stress ratio are able to change according to the service loading condition. To check the applicability and accuracy of this new procedure, axial load controlled random loading tests, with an exponential distribution of the peak to peak-stress, were carried out for plane mild steel specimens. Fatigue behavior patterns are then examined.